1. Field of the Invention
The present invention relates to a data processing system capable of playing multimedia presentations and relates more particularly to a data processing system that warns a user that the complete playback of a multimedia presentation will conflict with an upcoming calendar event.
2. Description of the Related Art
A data processing system may be capable of playing back, or displaying, multimedia presentations that may contain motion video or audio data. Such multimedia presentations are isosynchronous in nature; that is, timing characteristics are the basis for conveying information. For example, motion video may be optimally presented by presenting individual video frames in a particular order and at a particular rate of frames per unit of time. Similarly, audio, such as recorded or synthesized speech and recorded or synthesized music, may be optimally presented at a particular rate. Such multimedia presentations may be contrasted with, for example, graphical data or, ordinarily, textual information, whose rate of presentation to a human user of the data processing system is not normally significant. Under certain circumstances, however, even text can be considered isosynchronous, as where a text-to-speech process is used to convert the text to spoken audio speech. Similarly, if the text is presented to the user by scrolling it across a display screen, the scrolling rate, which may be measured in characters or in lines per unit of time, give the presentation of the text isosynchronous properties.
The optimal rate of presentation of the information in an object that contains isosynchronous data gives that object an optimal playback duration, which may be expressed in time. Some multimedia objects expressly state their duration; for example, the directory structure of audio compact discs may state the time duration of individual tracks. An isosynchronous data object differs in this manner from a non-isosynchronous data object such as a graphical image file--while both objects typically have a file size, which may be expressed in bytes, only the isosynchronous object also has a time duration, which may be expressed in seconds, minutes or hours or the like.
A data processing system may include an electronic calendar application which allows the user to maintain a schedule of upcoming events of interest to him. Calendar events may have a start time, a stop time and a duration. When adding a new event to a calendar, the calendar application may check the existing calendar events for any events that conflict in time with the event to be added. However, data processing systems, even those that include calendar applications, do not notify a user that a scheduled calendar event will conflict with the complete playback of an isosynchronous data object. Thus, there is a need for a data processing system that notifies a user that a scheduled calendar event will conflict with the complete playback of an isosynchronous data object.